Hydrogen is a gas that can be used as an efficient fuel as well as for production of electrical energy. The use of hydrogen gas has certain obvious advantages, such as reduced exhaust pollution problems compared to other combustion solutions, and is also a relatively efficient energy storage medium. One of the main obstacles in introducing the hydrogen economy in the society is, however, the difficulties related to physical storage of hydrogen. Requirements on a storage system are a low lifetime cost, high reliability, high safety and simple handling. The possibility to store gas, in particular hydrogen, in a practical manner is therefore a field of great concern.
There are many potential possibilities to store hydrogen gas; in metals as metal hybrids, in carbon nano-tubes, chemically in different solutions or simply in high pressure tanks. There is a lot of ongoing research around the world to find the optimal solution. The challenge is to find a system that meets all or at least most criteria at the same time.
In a typical prior art high pressure tank for storing hydrogen gas, a high pressure shell is provided with an opening for introducing and/or releasing gas. Different kinds of valve configurations are typically provided at the opening for ensuring capability to introduce high pressurized gas into the tank and for ensuring a reliable release of the gas from the tank. The procedures connected to storage and releasing of gas are typically based on physical connection of gas conduits and operation of valves. The valves are typically controlled by physical procedures or by different electrical means.
Frequent handling of valves as well as connection of gas conduits suffer typically from wear and mechanical failures, and since the gas storage has a high pressure in order to reduce the occupied volume, the handling has to be performed with extreme care to avoid accidents.
The problems with gas handling above were above identified concerning handling of hydrogen gas. However, corresponding problems are also present for any kind of gases.
One problem with prior art solutions of gas storage is that the requirements of low lifetime cost, high reliability, high safety and simple handling cannot be met at the same time.